Character changes from idiopathic cranial pachymeningoencephalitis.

A 66-year-old man with idiopathic cranial pachymeningoencephalitis was described. He suffered from left orbital pain, and character changes. He became short tempered, and was very attached to trifles. Two years prior to these symptoms, he had developed transient left abducent nerve palsy. Head MRI showed a thickening and enhancement of the dura mater on gadolinium-enhanced T1-weighted images, and high signal intensity lesions at bilateral frontal lobes predominantly in the white matter on T2-weighted images. Biopsies revealed microglial proliferation in the cerebral parenchyma, and mild lymphocytic perivascular infiltration. No evidence of intracranial infection was detected. We therefore treated him with methylprednisolone pulse therapy followed by oral prednisolone. His character became gradually normalized, and bilateral frontal lobe lesions seen on MRI disappeared. This is the first case to describe recurrent pachymeningoencephalitis with character changes, and symptoms were probably due to frontal lobe dysfunction.